From pattern diagnostics to Machine Learning in probabilistic estimation of precipitation from multi-satellite observations with emphasis on extremes and uncertainty quantification

Efi Foufoula-Georgiou, University of California, Irvine

Precipitation is the input to the hydrologic cycle and affects the water and energy balance at the local, regional and global scales. Precipitation extremes create hazards and endanger life, property and critical infrastructure. Under global warming, precipitation is expected to change in complex ways, including the mean annual precipitation, the duration of wet and dry spells, the seasonality, and the frequency and magnitude of extremes. In this talk, I will present recent results on two main aspects of precipitation: (1) global precipitation estimation from multi-satellite observations, and (2) assessment of the change of the space-time structure of storms under global warming. In global precipitation estimation from multi-satellite observations, a severely underdetermined inverse problem, I will discuss our path from physically-informed pattern diagnostics to a new Generative Diffusion model conditional on infrared dynamics and instantaneous passive microwave observations and show an impressive performance in capturing extremes and providing uncertainty quantification. In assessing precipitation changes relevant to hazards, analysis of cloud resolving models in historical and future simulations show that global warming will induce a “sharpening” of storms both in time and space, meaning that a larger proportion of rain will fall over fewer wet hours and over smaller areas, amplifying hazard potential for flooding and post-fire debris flows.

Bio:

Efi Foufoula-Georgiou is a Distinguished Professor at the University of California, Irvine, holding the Henry Samueli Endowed Chair in Engineering, with appointments in both the Departments of Civil and Environmental Engineering and Earth System Science. She has an extensive academic and research background, having previously served as a McKnight Distinguished Professor at the University of Minnesota, where she directed the NSF Science and Technology Center for Earth-surface Dynamics (NCED) and the St. Anthony Falls Laboratory. Her research focuses on hydrology, geomorphology, and scaling theories, particularly in relation to precipitation and landforms. Professor Foufoula-Georgiou has made significant contributions to her field, serving on numerous advisory boards, including the Water Science and Technology Board of NAS and the NSF Geosciences Advisory Council. Among her many honors are the John Dalton Medal from the European Geophysical Society and the Hydrologic Sciences Medal from AMS. She is a fellow of multiple prestigious organizations and was appointed by President Barack Obama to the Nuclear Waste Technical Review Board.